Flat coil dynamoelectric device with encapsulated preform

ABSTRACT

A discoidal, flat coil armature for a flat disc motor is formed by winding coils of wire on mutually spaced inner and outer ring structures. The inner ring structure surrounds a commutator body having segments with tangs. Automatic apparatus, including a rotating flier, a preform clamp and rotator, and a wire guide assembly, winds the coils and makes coil terminal connections to the commutator tangs before, during, and after the winding of the coils. The coils are tightly wound on the ring structures so that they form, along with the ring structures and the commutator body, an armature preform having a self-supporting shape. The parts of the finished preform are bonded together and to an armature shaft by a matrix of resinous material. When completed, the armature includes a thin-walled, active coil section having substantially radially extending active coil sides encapsulated in plastic and located between the inner and the outer ring structures, and also includes inner and outer coil end turns that are also encapsulated in plastic and that extend substantially circumferentially along the inner and the outer ring structures.

This is a continuation of application Ser. No. 650409, filed Sept. 13,1984.

SUMMARY OF THE INVENTION

This invention relates to a flat coil dynamoelectric device and to amethod for manufacturing the same. More particularly, this invention isconcerned with a discoidal armature of the type comprising plural, flatcoils wound from insulated wire, the armature having a thin walled, flatannular active coil section surrounding a center structure, including acommutator to which the several coils are connected. Those familiar withthe art will recognize that the invention is not necessarily so limited.For example, certain aspects of the invention could apply to themanufacture of dynamoelectric devices, such as field members, which donot include a commutator.

Many approaches have been used to manufacture flat coil dynamoelectricdevices, but the known techniques require the use of time-consuming andexpensive manual steps and/or the use of elaborate and extensiveequipment for winding and thereafter handling the coils as needed toform the completed devices.

An object of this invention is to simplify and thereby reduce the costof manufacturing flat coil dynamoelectric devices. To this end, adynamoelectric device of this invention is produced by firstconstructing a preform by winding coils of wire onto a preform framecomprising spaced, coaxial inner and outer frame members. The framemembers are each of a solid or unitary construction having aself-supporting shape. Preferably, the coils are so wound that theirinner and outer end turns substantially overlie the inner and the outerframe members, respectively, and securely engage surfaces thereof; thecoil sides extend substantially radially to the common axis of the framemembers; and the coil sides span between the two frame members. Thecoils are wound under sufficient tension, and the frame members built towithstand such tension, that the completed preform comprises aself-supporting body which may be handled by automatic materialshandling equipment in essentially the same manner it would be handled ifit were a solid piece. Upon completion of the preform, it isencapsulated in a matrix of resinous material to form the completeddynamoelectric device.

Another object of this invention is to provide an improved flat coilarmature and a method for producing the same. An armature of thisinvention is preferably produced by winding the armature coils on apreform frame comprising concentric inner and outer ring structureshaving surfaces over which the coil end turns are engaged. A commutatorbody is located within the bore of the inner ring structure and hastangs extending therefrom. Appropriate connections of the coil terminalwire portions to the commutator tangs are made before, during, and afterthe coils are wound. The commutator body is securely mounted within thebore of the inner ring structure and the coils are wound undersufficient tension that the wound assembly (termed an "armaturepreform") of the preform frame and the commutator have a self-supportingshape. The preform may, accordingly, be handled by automatic materialshandling equipment, there being no loose coils or wire leads requiringattention.

Either before or after the preform is wound, the commutator is mountedon an armature shaft and the preform and the shaft located within thecavity of a plastic molding machine, such as an injection moldingmachine, whereupon the inner and outer ring structures along with thecoil wires therebetween are encapsulated in a matrix of resinousmaterial. The matrix of resinous material also encapsulates thecommutator tangs and the lead wire connections thereto and surroundsportions of the armature shaft and the commutator body.

An armature made in accordance with this invention has a well defined,thin-walled active coil section with the active coil wires extendingalong substantially radial paths to maximize the efficiency with whichthe coils are affected by the magnetic fields within which they operate.The end turns of the coils are coursed over surface portions of theinner and outer rings shaped to retain the inner and outer end turns ofeach coil separated from one another and from the area of the activecoil sections.

Other objects and advantages will become apparent from the followingdescription and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an armature made in accordance with thisinvention.

FIG. 2 is an axial, end view of an armature preform and an armatureshaft, the preform and the shaft forming part of the armature of FIG. 1.

FIG. 3 is a fragmentary axial, end view of a preform frame and acommutator forming part of the preform of FIG. 2, and showing a firstarmature coil wound on the preform frame.

FIG. 4 is an axial, end view of the preform frame and a commutatorshowing the first three coils wound thereon in full lines and the fourthcoil in phantom lines.

FIG. 5 is a cross-sectional view of a portion of the armature preformtaken along line 5--5 of FIG. 2.

FIG. 6 is a simplified, cross-sectional view of tooling of a plasticinjection molding machine with the armature of FIG. 1 shown formedtherein.

FIG. 7 is a simplified diagrammatic and schematic view of an armaturewinding machine in accordance with this invention used to wind coils andform commutator connections to the coils to produce the armature preformof FIG. 2, and illustrating the armature preform frame at the windingstation of the machine.

FIG. 8 is an enlarged, fragmentary, elevational view, partly incross-section, of a portion of the machine of FIG. 7 with the armaturepreform frame and the commutator at the winding station.

FIG. 9 is an enlarged, fragmentary, exploded, perspective view of aportion of the machine of FIGS. 7 and 8 and including the preform frameand the commutator.

FIG. 10 is a fragmentary perspective view of the machine, the preformframe, and the commutator as viewed from a point of reference differentfrom that of FIG. 9, and showing the position of parts in readiness tocommence the winding of coils and the formation of commutatorconnections.

FIG. 11 is a fragmentary elevational view of parts of the machine,showing wire shielding and guiding structure by both full and phantomlines, along with a wire clamp and the preform parts, the machineelements and the preform parts being represented in the same positionreached in FIG. 10.

FIGS. 12, 14, 16, 18, 20 and 22 are each similar to FIG. 10 and show, insequence, the steps taken to loop the start wire of the first coil to bewound about a commutator tang in advance of the winding of such firstcoil.

FIGS. 13, 15, 17, 19, 21 and 23 are each similar to FIG. 11 but show theposition of the parts reached in FIGS. 12, 14, 16, 18, 20 and 22,respectively.

FIGS. 24 and 25 are similar to FIGS. 10 and 11, respectively, but showthe parts in readiness to wind the first coil on the preform frame.

FIGS. 26 and 27 are views similar to FIGS. 10 and 11, respectively, butshow the parts after the winding of the first coil is completed.

DETAILED DESCRIPTION

With reference to FIG. 1, an armature designed for use in a flat discmotor and made in accordance with this invention is generally designated40, and comprises a discoidal, encapsulated winding 42, a commutator 44,and an armature shaft 46. The armature shaft 46 is designed to engagebearings within the motor housing (not shown), and may be of anyconventional construction. The commutator 44 comprises a plurality ofcircumferentially spaced conductive segments 50 on a cylindrical body ofplastic press-fit on the shaft 46. The segments 50 each have means forconnection to terminal portions of the several armature coils, suchconnection means being shown in FIGS. 2 through 6 and comprisingcommutator tangs 52, there being one tang 52 forming part of each one ofthe segments 50.

The winding body 42 is of a circular, disc-like configuration, having anouter ring 54, an inner hub 56, and a circular web 58. The hub 56 isformed, as will be described below, so as to be adhered both to aportion of the commutator 44 and to a portion of the armature shaft 46.The construction is such that the encapsulated winding 42 is securelyaffixed to the commutator 44 and the shaft 46 so that, when in use,rotation imparted to the winding body 42 by the motor field magnets (notshown) will be transmitted directly to the shaft 46.

The encapsulated winding 42 includes plural coils wound from insulatedwire, preferably insulated copper wire, which are encapsulated in aresinous material. The resinous material and the wire sections formingthe web 58 have a minimal thickness and are so formed that wire strands(as indicated by W in FIG. 1), may be exposed at the surfaces of the web58. The radial dimensions of the web 58 are determined by the designparamaters of the motor with which the armature 40 is to be used. Morespecifically, permanent magnet pole pieces in the motor housing (notshown) or the like will be located as close as possible to the web 58and the radial dimensions of the web 58 are designed to accomodate thedimensions of the pole pieces. The pole pieces typically would belocated on one side of the web 58, with steel located on the other sideof the web 58, it being desirable in the construction of such motorsthat the spacing needed to accomodate the web 58 between the pole piecesand the steel or other motor parts be kept to a minimum.

As will be described below, the portions of the armature coils lyingwithin the web 58 are arrayed on lines extending generally radially fromthe axis of the armature shaft 46, and the portions of the coils locatedwithin the outer ring 54 and the hub 56 comprise end turns which arelocated outside of the ambit or projection of the pole pieces, such endturns extending generally coaxially around the axis of the armatureshaft 46.

With reference to FIGS. 2 through 6, the manufacture of the armature 40may be accomplished entirely automatically by a process wherein coils ofwire are wound from a continuous, uninterrupted length of wire onto apreform frame 59. Frame 59 comprises a pair of coaxially oriented andsubstantially coplanar frame members, namely an inner ring 60, which maybe press-fit, hot-welded, molded or otherwise fixedly mounted on thecommutator 44, and an outer ring 62 extending circularly around andspaced from the inner ring 60. The inner ring 60 comprises a disc-like,thin-walled toroidal, main body portion 64, the front and rear surfacesof which may be planar and further comprises a plurality of inner coilforming protrusions or lugs 66 projecting forwardly from the main bodyportion 64. (For convenience, the term "forward" as used herein, refersto the end of the armature where the coils are connected to thecommutator tangs 52.) The lugs 66 are preferably in the form of L-shapedfingers or hooks and cooperate with the adjacent forward face of theinner ring 60 to form inner coil end turn receiving channels 68. Theouter ring 62 comprises a disc-like, thin-walled toroidal main bodyportion 69 having planar front and rear surfaces and further comprisesplural, substantially radially extending outer coil forming lugs 70protruding from the main body portion 69. In addition, the outer ring 62comprises a rearwardly extending annular flange 72 surrounding its bore62A. For reasons which will appear below, the bore 62A of the main bodyportion 69 of the outer ring 62 tapers inwardly from front to rear asmay be best seen in FIGS. 5 and 8.

Both the inner and the outer rings 60 and 62 may be made from anon-conductive material having sufficient strength, stability, andrigidity to have a self-supporting shape and to withstand the loadsapplied during and after manufacture. A glass-filled nylon is an exampleof a material suitable for this purpose. Numerous other thermoset orthermoplastic materials may be used. Materials other than plastic, suchas metal having an insulating coating or amorphous materials would alsobe suitable. For proper operation of the armature 40 it is necessarythat the rings 60 and 62 be non-magnetic. A resinous material ispreferred because the rings can readily and inexpensively bemanufactured in large quantities therefrom.

The outer end turns of each armature coil extend between a pair ofcircumferentially spaced outer coil forming lugs 70 and the inner endturns extend between a pair of circumferentially spaced inner coilforming lugs 66 with the coil sides which form the active coil portionsspanning between the inner and the outer rings 60 and 62. The locationof the armature coils on the preform 59 may be best understood withreference to FIGS. 3 and 4, which show a first coil 74 wound on theinner and the outer rings 60 and 62. The first coil 74 has a firstactive side 74A and a second active side 74B. These lie along linesextending nearly radially from the center axis of the preform frame 59.The coil 74 further includes inner end turns 74C and outer end turns 74Dspanning respectively across spaced inner coil forming lugs 66 and outercoil forming lugs 70. Because the outer coil forming lugs 70 projectsubstantially radially in the embodiment illustrated in the drawings,whereas the inner lugs 66 extend generally parallel to the center axisof the frame 59, the coil sides 74A and 74B along with the inner coilend turns 74C lie along the front of the preform frame 59. In contrast,the outer end turns 74D are formed over the outer periphery of the outerring body 69 alongside the outer coil forming lugs 70 which they engageand then along the backside of the body of the outer ring 62. Themid-portion of the outer end turns 74D stretching along the backside ofthe outer ring body 69 lie against the outer periphery of the annularflange 72 and are thereby prevented from entering the area occupied bythe active coil sides 74A and 74B, i.e., the area of the web 58 of thecompleted armature. Since the inner end turns 74C overlie inwardlydirected surfaces of a pair of inner coil forming lugs 66 and the outerend turns 74D are constrained by the outer coil forming lugs 70 theyengage to overlie outwardly directed surface portions of the outer ringbody 69, the preform frame 59 effectively constitutes a coil form thatdetermines the shape of the first coil 74 and all subsequent coils woundthereon.

As will be further described below, in the illustrated embodiment, whenthe winding of the armature 40 is commenced, the start end S of the wireW forming the first coil 74 is wrapped around one of the commutatortangs 52 (such tang being designated 52A in FIGS. 3 and 4) so that thestart end S is extended from the selected tang 52A and coursed adjacentone of the inner coil forming lugs 66 and the wire is then wound intothe first coil 74.

After the first coil 74 is wound as shown in FIG. 3, the finish wireportion thereof, designated F, is advanced to the commutator tang 52Bnext adjacent the second active side 74B of the first coil 74, loopedaround the tang 52B, and the wire then coursed to wind a second coil 76shown in FIG. 4. The process is repeated then to wind the third coil 78shown in FIG. 4, and so forth. In the embodiment of the armature shownin the drawings, there are sixteen coils, all sixteen being shown inFIG. 2. The first coil wound is identified in FIG. 2 by its coil sides74A and 74B, the second coil by its sides 76A and 76B, the third coil byits sides 78A and 78B, the fourth coil wound by its sides 80A and 80Band also by its outer end turns 80D, the fifth by its sides 82A and 82B,the sixth by its sides 84A and 84B, and the seventh by its sides 86A and86B and also by its outer end turns 86D. The eighth through thefifteenth coils are designated in FIG. 2 respectively by referencenumbers 88, 90, 92, 94, 96, 98, 100 and 102, the lead lines to suchcoils extending from the reference number toward the first coil sidesthereof. Finally, the sixteenth coil wound is designated in FIG. 2 byits first coil side 104A and its second coil side 104B. Extending fromthe last side turn of coil side 104B is a terminal finish wire end Tthat is looped around the same commutator tang 52B about which the startwire S is looped.

It may be observed in FIGS. 2, 3 and 4 that there are sixteen commutatortangs 52, sixteen inner coil forming lugs 66, and sixteen outer coilforming lugs 70. However, it is to be understood that other geometriesare possible involving greater or lesser numbers of tangs, lugs, andcoils. Also, it will be noted in the drawings that each coil spansacross three of the inner coil forming lugs 66 and three of the outercoil forming lugs 70 and it will further be observed, as may beappreciated best from a study of FIG. 4, that there is a spacing betweensubsequently wound pairs of coils of two of both the inner and outercoil forming lugs 66 and 70. Accordingly the coils are effectively woundin layers of three each. Thus it can readily be appreciated, withreference to FIG. 4, that the fourth coil wound, which is shown byphantom lines 80, spans across the first side 74A of the first coil 74.Those familiar with armature windings will recognize the winding patternis of a type known as retrogressive wave winding. A progressive wavewinding could also be accomplished within the purview of this invention,as well as both progressive and retrogressive lap windings. With thewave winding pattern illustrated, it will be observed that the secondset or layer of three coils is 1/16th offset in a circumferentialdirection from the first layer. The same is true for subsequent layers.If there were to be 18 coils, each layer would be 1/18th offset from theadjacent layer and so forth. However, as mentioned above, many otherwinding patterns and geometries may be produced.

The completed assembly, shown in FIG. 2, of the preform frame 59, thecoils 74-104 wound on the frame 59, and the commutator 44, to which thecoil terminal wires are connected is termed an "armature preform" hereinand is referred to generally by reference number 105. The coils arerelatively tightly wound with as many turns per coil as dictated by theperformance requirements of the motor with which the armature is to beused.

With reference to FIG. 5, a portion of the fully wound preform 105 andthe armature shaft 46 are shown in cross-section. The first wound side74A of the first wound coil 74 is illustrated in FIG. 5, such coil sidebeing shown to be flush against the forward surfaces of both the innerand outer rings 60 and 62. Parts of the fourth wound coil 80 span overthe coil side 74A as mentioned above and are therefore visible in FIG.5, these being parts that constitute, respectively, the inner and outerend turns. Inner and outer end turns of the seventh wound coil 86,appear in FIG. 5, these parts being coursed around the same inner andouter coil forming lugs 66 and 70 illustrated in FIG. 5 that are engagedby the first coil end turns 74C and 74D. Also shown in FIG. 5, loopedabout the tang 52 illustrated therein, is a wire loop 106 thatinterconnects the second side of coil 92 with the first side of coil 94.(Coils 92 and 94 are not shown in FIG. 5.)

It can be appreciated by an inspection of FIGS. 2 through 5 that thecompleted preform 105 has a circular array of tightly wound coils eachof which tends to pull the inner ring 60 toward the outer ring 62. Whenwinding devices having an even number of slots and coils, each coil isdiametrically opposed to an essentially identical coil tending to pullthe inner ring 60 in the opposite direction. Accordingly, the coil sidesspanning between the inner and outer rings 60 and 62 are under tensionand function mechanically somewhat like the spokes of a conventionalbicycle wheel to hold the inner ring 60 and the outer ring 62 togetherand to resist relative movements of any kind therebetween. The sameresult will also obtain in those cases in which the device has an oddnumber of slots and coils or other configuration wherein each coil willbe substantially, but not precisely, diametrically opposed by anessentially identical coil. For this reason, the fully wound preform hasa substantially self-supporting shape and can be moved about ormanipulated by mechanical devices as if it were a solid, one-piece part,there being no loose or highly flexible parts requiring special orseparate handling.

After the winding of the preform 105, fusing or hot-staking of each ofthe commutator tangs 52 is performed, as is conventionally done afterthe winding of other types of armatures having commutators with tangs.By such process, the free ends of the tangs 52 are bent, and therebyfolded upon the wire portions looped therearound, from their positionsalmost parallel to the axis of the preform 105, such condition beingshown by phantom lines in FIG. 5, to positions wherein they areessentially perpendicular to such axis using an electrode thatelectrically heats the tangs and vaporizes the wire insulation, therebyinsuring both secure electrical and secure mechanical connections to bemade. Also, after the winding of the preform 105, the armature shaft 46is press-fit within the bore of the commutator 44.

After processing as described above, the preform 105 and the armatureshaft 46 can be placed in an appropriate plastic molding machine, suchas an injection or a compression molding machine, to encapsulate thewindings as well as the inner and outer rings 60 and 62 in a matrix ofmolded resinous material which serves also to bond the various parts ofthe preform and the armature shaft together. One such operation isillustrated in FIG. 6 wherein the preform 105 is shown positioned in anappropriately shaped cavity formed in confronting mold members 110 and112. Molten plastic has been injected, using techniques that may beentirely conventional, into the mold cavity to form a pressure-shapedmolded resinous matrix 114 that covers, and is effectively integralwith, the inner and outer rings 60 and 62 to form therewith, and withthe coil portions supported thereby, the rear portion of the armaturehub portion 56 and the entire outer margin 54 of the completed armature40. The web 58 is similarly formed by an encapsulation of the coil sideturns in the molded matrix 114. The forward part of the hub portion 56is formed by the molten resin, which serves to encapsulate the innercoil forming lugs 66, the wire portions extending therearound, and alsothe tangs 52 and the wire parts that loop therearound. The resinousmaterial used to form the molded matrix 114 may comprise any one ofnumerous available thermoset or thermoplastic materials. Polyethyleneterephthalate (PET) is an example of a suitable material.

The molding operation may occur using various different processes withthe advantage that the parts of the preform 105, because they areself-supporting and of a substantially rigid configuration, can simplybe placed into the mold cavity either by hand or by automaticallyoperating machinery. As a preliminary to the molding operation, one mayoptionally flatten the coil sides because of the desirability of havingthe web 58 of absolute minimum thickness.

Apparatus for winding the coils and forming the commutator connectionsis illustrated in FIGS. 7 through 27. FIG. 7 is a simplified, somewhatdiagrammatic and schematic view of the machine which is generallydesignated 120.

The winding machine 120 has a flier spindle 122 driven by a motor 124for rotation about a flier axis 126. A flier 128 is mounted on thespindle 122 for rotation therewith. Wire from a suitable source of wire130 placed under tension by dereeler 131, which may be entirelyconventional, is coursed through the spindle 122 and outwardly therefromaround a wire exit pulley 132 adjacent to the flier 128 and a flierpulley 134 at the free end of the flier 128. The wire W may be held by aclamp 136 which may be associated with a cutter mechanism (not shown)for severing the wire portions between the winding of subsequently woundarmatures. Those familiar with flier type armature winding machines willrecognize that the structure as thus far described in FIG. 7 may beentirely conventional, various types of flier-type winding machinesbeing well known. For this reason the flier drive is not described infurther detail herein.

The machine 120 illustrated in FIG. 7 further includes a winding formassembly 138, that will be further described below, and a preform clampand rotator assembly, generally designated 140. The preform clamp androtator assembly 140 holds the inner and outer rings 60 and 62 inrelatively fixed coaxial, substantially coplanar, and rotationalpositions, only the outer ring 62 being visible in FIG. 7.

The clamp and rotator assembly 140 includes a drive motor 142 and aclamp release cylinder 144 which, together with the remainder of theassembly 140 are mounted on a frame 146 which can be affixed to the bedof the machine (not shown).

With continued reference to FIG. 7, and also with reference to FIGS. 8and 9, the commutator 44 is shown clamped by a split collet 148 which isheld in clamping relation thereto by a spring washer assembly 150surrounding a collet operating shaft 152 and biasing a collet operatingram 154 affixed to the end of the collet operating shaft 152 to the leftas shown in FIG. 8 so that the split collet 148 gripping1y engages thecommutator 44. It will be noted in FIGS. 7 and 8 that a collet operatinglever 156 may be driven by the clamp release cylinder 144 so as toovercome the bias of the spring washer assembly 150 and thereby causethe collet operating ram 154 to be moved to the right as shown in FIG.8, whereupon the gripping pressure exerted by the collet 148 upon thecommutator 44 will be reduced so as to permit insertion or removal ofthe commutator.

The collet operating ram 154 cooperates, as is obvious, with a colletcam 158 to cause the collet 148 to grip the commutator. The collet cam158 forms part of a collet housing 160 which has on its forward face161, i.e. the face confronting the winding form assembly 138, aforwardly extending projection or key 162 adapted to fit within a notch164 in the rear face of the inner ring 60 (see FIG. 9) for purposes ofholding the inner ring 60 in a predetermined rotary relationshiprelative to the outer ring 62 as will be made more apparent below.

The housing 160 is generally tubular and has four slots 166 spacedequally therearound within which are located clamp levers 168 mountedfor pivotal movement on the housing 160 by pivot pins 170 and which areformed at their outer ends to innerfit within the bore of the outer ring62. Three of the levers 168 are formed so as to snugly mate with andclamp against the tapered inner bore surface 62A of the outer ring 62.The fourth arm 168 is formed with a projection or key 172 for engaging acooperating notch 174 (see FIG. 9) in the bore 62A of the outer ring 62so that the outer ring 62 is held in a predetermined rotary positionrelative to the four clamp levers 168. The levers 168 are each biased bysprings 176 connected thereto and to the housing 160 so that the freeends of the levers 168, i.e., those ends designed to engage the bore62A, are biased outwardly to securely hold the outer ring 62. At suchtime as the collet release cylinder 144 is energized to release the gripon the commutator 44, the outer ring clamp levers 168 are caused to bepivoted inwardly of the bore 62A and become disengaged from the outerring 62 by virtue of engagement of the margins of a groove 178encircling the collet ram 154 with pawl-like, radially inwardlyprojecting lugs 169 forming parts of the levers 168.

The collet mechanism described above, including the collet 148, thecollet ram 154, the housing 160, and the levers 168 are all rotatableabout a collet axis 180 (see FIG. 7) coincident with the axis of thecommutator 44 and the preform frame 59. In FIG. 7, the collet axis 180is shown parallel to and offset from the flier axis 126 (as it wouldappear in a plan view), a condition necessary to enable the coils to besuccessively wound about axes which are offset from the axis of thepreform frame 59. As will be described below, the collet parts arecaused to rotate by the clamp and rotator assembly drive motor 142through a repeating series of steps to effect connection of the wire Wto the commutator tangs and to wind the coils.

Referring to FIGS. 8 and 9, the winding form assembly 138 includes awinding form 190 which, as conventional, is mounted by a bearing locatedwithin a housing 192 on the end of the flier spindle 122 and includes apair of winding form support plates 194 and 196 on which is supported aform mounting block 197 on which wire guide plates 198, 206, and 214, tobe described below, are mounted. The winding form 190 includes an outerwire guide plate 198 which has a concavely curved surface 200 adapted toshield a portion of the outer ring 62 to prevent the wire sliding alongthe plate 198 from engaging the outer ring 62. Adjacent curved surface200, the outer guide plate 198 has sloping lower and upper wire guideedge surfaces 202 and 204, respectively, for guiding the wire around theouter coil forming lugs 70 across which extend the outer end turns ofthe coil to be wound.

The winding form 190 further includes an inner wire guide plate 206having sloping lower and upper wire guide edge surfaces 208 and 210,respectively, for guiding the wire around the inner coil forming lugs 66across which the inner end turns of the coil extend. The center portionof the face of the inner guide plate 206 has a recess 212 designed toprovide a pocket for the inner coil forming lugs 66 across which theinner end turns of the coil extend and is provided with an arcuate wireguide lip 213 designed to be located between the pocketed lugs 66 andthe adjacent commutator tangs 52. As the flier 128 rotates during thewinding of a coil to draw wire across the inner guide plate 206, thewire slides along the surface 208 and, as it enters the recess 212,engages along one side of one of the inner coil forming lugs 66 and isthen forced by the arcuate wire guide lip 213 into the inner end turnreceiving channels 68 shown in FIG. 5. As the flier 128 continues torotate, the wire is guided by the upper edge guide surface 210 to theother one of the inner coil forming lugs 66 which it engages. The outerwire guide plate 198 is spaced from the inner wire guide plate 206 by anintermediate guide plate 214 having a polished, planar guide surface 215provided to closely confine the coil side turns adjacent the frontsurface of the rings 60 and 62 as the winding progresses.

Referring to FIGS. 7, 9, and 10, an inner pin and commutator shieldassembly 216 is provided to prevent the wire from engaging thecommutator tangs or the wrong inner coil forming lugs 66. The assembly216 includes an inner pin and commutator shield plate 218 to which isrigidly attached a positioning arm 220 that is pivotally supported by aclevis 222 at the end of a drive rod 224 of an inner pin and commutatorshield positioning air actuator 226. The end of the positioning arm 220remote from the shield plate 218 has a guide pin 228 that rides in anarcuate guide slot 230 in a guide plate 232.

The inner pin and commutator shield plate 218 has a recess 234 shown inFIG. 9 for receiving selected ones of the inner coil forming lugs 66 andthe commutator tangs, the recess being located in the face of the shieldconfronting the preform frame 59. The shield 218 is selectively locatedin either one of two positions, namely an extended position and aretracted position. FIG. 27 shows in full lines the extended positionwhich the shield plate 218 occupies during the time a coil is beingwound. There it will be noted that the shield plate 218 overlies asufficiently large portion of the front face of the inner ring 60 thatonly three of the inner coil forming lugs 66 are fully exposed, thesebeing the same three pins pocketed by the central recess 212 of theinner guide plate 206. The shield plate 218, accordingly, shields all ofthe other inner coil forming lugs 66 as well as all of the commutatortangs 52 during the winding of a coil and thereby prevents the wire fromhooking any portion of the inner ring 60 but for the lugs 66 about whichthe inner coil end turns are being formed. The face of the shield plate218 opposite the face confronting the inner ring 60 is concavelycontoured as needed to permit the wire to enter the center recess 212 ofthe inner guide plate 206 as the flier 128 rotates to wind a coil. Thefree end edge, designated 236, of the shield plate 218 is also contouredto assist in guiding the wire into the channels 68. In FIGS. 26 and 27it can be seen that, in the extended position of the shield plate 218,its free end edge 236 is located closely adjacent to the inner wireguide plate 206. In the retracted position of the shield plate 218,shown in FIGS. 10 through 23 and in phantom lines in FIGS. 26 and 27, itis moved horizontally away from the inner guide plate 206 and is alsopivoted in a counterclockwise direction, as viewed therein, for reasonswhich will become apparent.

FIGS. 10 through 27 show in sequence the manner in which the apparatusof this invention operates to wind the preform shown in FIG. 2. First,it may be noted that FIG. 11 shows the same position of the parts thatare illustrated in FIG. 10. The same scheme is followed throughout theremaining FIGS. 12 through 27, with the odd numbered figuresillustrating the parts in the same position as the immediatelypreceeding figure. Also, the odd numbered figures beginning with FIG. 11illustrate the winding form assembly 190 by phantom lines 190A. Themargins of the winding form guide surfaces that cooperate with the innerring 60 and the outer ring 62 to determine the shape of the coils areindicated by phantom lines 190B.

In general, FIGS. 10 through 23 illustrate a sequence of steps that maybe taken to loop the start wire end S around its associated tang 52A inpreparation for the winding of the first coil 74. FIGS. 24 and 25illustrate the position of parts at the commencement of the winding ofthe first coil 74 and FIGS. 26 and 27 show the position of the parts atthe end of the winding of the first coil 74. After the parts havereached the position shown in FIG. 27, the sequence of steps shown inFIGS. 14 through 27 are repeated for each coil to be wound. The loopingof the wire portions about the tangs 52 is accomplished by a series ofrotary movements of both the flier 128 and the preform assembly of therings 60 and 62 and the commutator 44. During the looping operation, theshield plate 218 is located in its retracted position to enable the wireto be guided by the inner guide plate 206 along the side of the tang 52Aaround which it is to be looped, as is illustrated in FIGS. 12 and 13.To enable the rotary positions of the preform assembly to be quicklygrasped, the key 172 engaging in the outer ring notch 174 is marked withhatch lines in the odd numbered figures beginning with FIG. 11, and itshould be recognized that the hatch lines do not in this case representthat the part is shown in cross-section.

Those familiar with flier-type armature winding machines will appreciatethat the process for winding the armature preform and making theappropriate connections to the commutator tangs is related to proceduresdisclosed in U.S. Pat. Nos. Re. 27,893 and 3,705,459, and will be ableto comprehend the winding and tang looping procedures by studying FIGS.3, 4, and 10 through 27 herein. At the commencement of the tang loopingand coil winding process, the inner and outer rings 60 and 62 along withthe commutator 44 are clamped in the position shown in FIGS. 10 and 11and the free end of the wire W is held by the wire clamp 136. Thelooping of the start wire S around a tang 52 is begun by rotation of theflier in a "forward" direction, which is the same direction in which theflier is rotated to wind the coils. This is counterclockwise or"top-going" as viewed in FIGS. 10 and 12. The wire W is thereby extendedalongside the outer coil forming pin designated 70A in FIG. 13 and alsoalongside the commutator tang 52A around which the start wire portion Sis to be looped. The preform 105 is then rotated in a clockwisedirection, as indicated by the arrow 242 in FIGS. 14 and 15, through anangle of slightly less than 90 degrees. During this rotary movement ofthe preform 105, the section of wire extending from the tang 52A to theflier pulley 134 is prevented by the shield plate 218 from hooking anyof the tangs other than tang 52A. At the same time, the outer coilforming lug 70A moves out of engagement with the wire W, so that thelength of the section of the wire W between the clamp 136 and the flierpulley 134 is shortened. Those familiar with armature winding machineswill recognize that the dereeler 131 may be used to substantially removethe slack wire condition that would result from the shortening of suchwire section.

After the clockwise rotation of the preform frame 59 shown in FIGS. 14and 15, the flier is rotated further in the forward direction asindicated by the arrows in FIGS. 16 and 17 through an angle ofapproximately 60 degrees in order to more securely hook the wire on thetang 52A. The wire is then looped around the tang 52A by rotating thepreform frame 59 in a clockwise direction, as indicated by the arrows inFIGS. 18 and 19, through an additional angle on the order of 50 to 60degrees which causes the tang 52A to move under the shield plate 218.The section of the wire W between the tang 52A and the flier pulley andalso the section of wire between the flier pulley 134 and the tang 52Aextend over the end edge of the tang shield plate 218 and the wire isalmost completely looped around the tang 52A.

After the parts have reached their positions shown in FIGS. 18 and 19,the flier is again rotated in its forward direction throughapproximately 60 degrees to complete the looping of the wire about thetang 52A as shown in FIGS. 20 and 21. During the increment of flierrotation between the positions of parts illustrated in FIGS. 18 and 19and the positions illustrated in FIGS. 20 and 21, the stretch of wirebetween the tang 52A and the flier pulley 134 begins sliding along theupper wire guide surface 210 of the inner guide plate 206 so that thewire is guided to a position wherein it partly lies between the innerring lug 66 next adjacent the tang 52A and the next adjacentcounterclockwise inner ring lug 66. Accordingly, the preform 105 maythen be further rotated to the position shown in FIGS. 22 and 23 tobring the lug 66A into engagement with such stretch of wire whereuponthe preform parts and the flier are positioned to initiate the windingof the first coil 74. At or before the commencement of the winding ofthe first coil, the shield actuator 226 is energized to move the tangshield plate 218 into its maximum shielding or extended position shownin FIGS. 24 and 25. Thus, the shield plate 218 is pivoted in theclockwise direction and translated horizontally toward the winding formassembly 190. The flier may then be rotated in its forward direction towind the first coil 74. During the winding operation, the wire isprevented from engaging the commutator tangs and all but the intendedinner ring lugs 66 by the shield plate 218.

During the winding of the first coil 74, the section of wire between thecommutator tang 52A and the clamp 136 is severed. This is preferablydone immediately adjacent the tang 52A and may be accomplished invarious ways. The presently preferred method would be to cause the wireto be severed against the edge of the tang by abruptly moving the clamp136 away from the commutator 44 clamped in the winding station by theclamp and rotator assembly 140. This method is described in U.S. Pat.No. 3,812,577, and a further discussion of the method or of apparatusfor accomplishing the same is deemed unnecessary.

A comparison of FIG. 27, showing the first coil 74 fully wound, and FIG.13, reveals that the stretch of wire leading to the flier is inapproximately the same orientation and that it leads to the flier froman outer coil forming pin 70 shown in FIG. 27 that is in the sameposition as the outer coil forming lug 70A about which the lead wire washooked in the position shown in FIG. 12. Accordingly, the parts are inposition when the winding of the first coil is completed to initiate thelooping of the terminal end of the first coil 74 about the next adjacenttang 52B. The first step is to return the tang shield plate to its upperand outer or retracted position, as is indicated by phantom lines inFIGS. 26 and 27, to expose the tang 52B for engagement by the wire. Thesequence of steps illustrated and described in connection with FIGS. 14through 27 are then repeated to accomplish the complete looping of thewire around the tang 52B and the winding of the second coil 76. Thesesame steps are then repeated throughout the winding of the armatureuntil all sixteen coils are wound.

At the end of the winding operation, the finish wire T of the last woundcoil 104 is looped around the same tang 52A about which the start wire Swas looped by a repetition of the steps illustrated and described inconnection with FIGS. 14 through 23. The next step is to sever the wirebetween the flier pulley and the wound armature. Again, this may beaccomplished in known ways, the method described in U.S. Pat. No.3,812,577 being preferred for this purpose.

Those familiar with the art of armature winding will recognize that theaforedescribed steps for winding the armature may be varied fordifferent armature configurations. Some of the steps may not be neededfor certain armature configurations, while others may require additionalsteps.

The operation of the machine 120 is controlled by machine controlcircuitry, schematically illustrated at 250 in FIG. 7, by which themotors 124 and 142 and the actuators 142 and 226 are selectvelyenergized to perform their functions in proper sequence. Those familiarwith flier-type armature winding machines will recognize that controlcircuitry used for armature rotators, such as that shown in U.S. Pat.No. 3,673,878, may be used for controlling the clamp and rotatorassembly drive motor 142. More recently developed electronic controlledrotators, which are well known and widely used in the art, could also beused. Electronic controls for operating fliers are also well known inthe industry; U.S. Pat. No. 4,163,931, discloses one form of circuitryfor this purpose. Because the machine control 250 could take variousforms and may be old and well known, it is not further illustrated ordescribed herein.

The preform 105 described above includes the commutator 44. Such ispreferred in the case of armature winding because all of the commutatorconnection steps are performed entirely automatically as the windingprogresses. The preform 105 does not include the armature shaft 46although it could optionally be mounted in place before the armature iswound. It clearly is an advantage to have the armature shaft 46 in placewhen the resinous material is molded so such material will be engagedwith the shaft 46 as shown in FIGS. 1 and 6.

Although the preferred embodiment of the present invention has beendescribed, it will be understood that various changes may be made withinthe scope of the appended claims.

We claim:
 1. A flat coil dynamoelectric device comprising asubstantially rigid preform having an integral outer frame structurehaving a central bore, a self-supporting shape, and being substantiallysymmetrical about a center axis; an integral inner frame structurehaving a central bore and being substantially symmetrical about saidcenter axis located within said central bore of said outer framestructure and having a self-supporting shape; plural coils of wireforming a complete set of coils for said device wound on said framestructures, said coils having sides spanning between said framestructures and end turns extending generally along said framestructures, said frame structures of said preform being held in mutuallyspaced relation by said coils, and a matrix of resinous materialencapsulating said preform.
 2. The device of claim 1 wherein said devicecomprises an armature, said inner and outer frame structures compriseinner and outer ring structures, respectively, and said device furtherincludes a commutator in the bore of said inner ring structure.
 3. Thearmature of claim 2 wherein said inner and outer ring structures eachhave lugs around which said coils are wound.
 4. A flat coil armaturecomprising a preform having an outer frame structure having aself-supporting shape and being substantially symmetrical about a centeraxis, an inner frame structure substantially symmetrical about saidcenter axis located within and substantially coplanar with said outerframe structure and having a self-supporting shape, plural coils of worewound on said frame structures, said coils having sides spanning betweensaid frame structures and end turns extending generally along said framestructures, said inner and outer frame structures comprising inner andouter ring structures, respectively, each having lugs around which saidcoils are wound, said outer ring structure having a circular flangeengaged by the outer end turns of said coils and preventing said outerend turns from entering the area between said ring structures, a matrixof resinous material encapsulating said frame structures and said coils,and a commutator in the bore of said inner ring structure.
 5. Thearmature of claim 3 wherein said lugs on said outer ring structureproject outwardly from said outer ring structure with respect to theaxis of said ring structures.
 6. A flat coil armature comprising apreform having an outer frame structure having a self-supporting shapeand being substantially symmetrical about a center axis, an inner framestructure substantially symmetrical about said center axis locatedwithin and substantially coplanar with said outer frame structure andhaving a self-supporting shape, plural coils of wire wound on said framestructures, said coils having sides spanning between said framestructures and end turns extending generally along said framestructures, said inner and outer frame structures comprising inner andouter ring structures, respectively, each having lugs around which saidcoils are wound, said lugs on said outer ring structure projectingoutwardly from said outer ring structures with respect to the axis ofsaid ring structures, said lugs on said inner ring structure includingsurface portions facing generally toward said axis, said coils beingwound from turns of wire coursed around a pair of said lugs on saidouter ring structure and said surface portions of a pair of said lugs onsaid inner ring structure, a matrix of resinous material encapsulatingsaid frame structures and said coils, and a commutator in the bore ofsaid inner ring structure.
 7. The armature of claim 6 wherein said outerend turns are formed around the outer margin of said outer ringstructure and hook over spaced pairs of said lugs projecting therefrom.8. The armature of claim 6 wherein said lugs on said inner ringstructure are hook-shaped and form with the adjacent face of said innerring structure wire-receiving grooves, and wherein said inner end turnsare located substantially within said grooves.
 9. The armature of claim8 wherein said outer end turns are formed around the outer margin ofsaid outer ring and hook over spaced pairs of said lugs projectingtherefrom.
 10. The armature of claim 2 wherein said ring structures eachcomprise generally circular, thin-walled body members.
 11. The armatureof claim 10 wherein said ring structures have substantially coplanarforwardly facing surfaces and said coil sides overlie and span betweensaid forwardly facing surfaces.
 12. A flat coil armature comprising apreform having an outer frame structure having a self-supporting shapeand bieng substantially symmetrical about a center axis, an inner framestructure substantially symmetrical about said center axis locatedwithin and substantially coplanar with said outer frame structure andhaving a self-supporting shape, plural coils of wire wound on said framestructures, said coils having sides spanning between said framestructures and end turns extending generally along said framestructures, said inner and outer frame structures comprising inner andouter ring structures, respectively, said ring structures eachcomprising generally circular, thin-walled body members, said ringstructures having substantially coplanar forwardly facing surfaces, saidcoil sides overlying and spanning between said forwardly facing surfaceswith said inner end turns extending along said forwardly facing surfaceof said inner ring structure a matrix of resinous material encapsulatingsaid frame structures and said coils, and a commutator in the bore ofsaid inner ring structure.
 13. The armature of claim 12 wherein saidouter end turns extend over the outer periphery and along the backsideof said outer ring structure.
 14. The armature of claim 13 wherein saidouter ring structure has a rearwardly extending circular flange engagedby the outer end turns of said coils and preventing said outer end turnsfrom entering the area between said ring structures.
 15. The armature ofclaim 14 wherein said coils are wound under tension so that each coilexerts a force tending to pull said rings toward one another.
 16. Thearmature of claim 15 wherein for each of said coils there is asubstantially diametrically opposed one of said coils tending to pullsaid rings together in the opposite direction.
 17. The armature of claim2 wherein said coils are wound under tension so that each of said coilstends to pull said rings toward one another.
 18. The armature of claim17 wherein for each of said coils there is a substantially diametricallyopposed one of said coils tending to pull said rings together in theopposite direction.
 19. A substantially rigid preform for a flat coildynamoelectric device comprising an integral ccouter frame structurehaving a central bore, a self-supporting shape, and being substantiallysymmetrical about a center axis, an integral inner frame structurehaving a central bore, substantially symmetrical about said center axislocated within the central bore of said outer frame structure and havinga self-supporting shape, and plural coils of wire forming a complete setof coils for said device wound on said frame structures, said coilshaving sides spanning between said frame structures and end turnsextending generally along said frame structures, said frame structuresbeing held in mutually spaced relation solely by said coils.
 20. Thepreform of claim 19 wherein said inner and outer frame structures eachhave lugs around which said coils are wound.
 21. The preform of claim 19further including a commutator in the bore of said inner framestructure.
 22. The preform of claim 19 wherein said frame structureshave substantially coplanar forwardly facing surfaces and said coilsides overlie and span between said forwardly facing surfaces.
 23. Thepreform of claim 22 further including a commutator in the bore of saidinner frame structure.